Paralytic shellfish toxin. (Photo: National Research Council of Canada)
Paralytic shellfish toxin may have spread southward
Friday, November 23, 2012, 23:20 (GMT + 9)
The paralytic shellfish toxin that affected Tasmania's east coast and forced the closure of fishing grounds from Ansons Bay to Marion Bay may have moved southward. Tests are being conducted to figure out how far the toxin has spread.
So far, the fisheries affected are mussel, rock lobster, abalone, and scallop. Commercial season never even took off.
Acting Deputy Secretary of the Department of Primary Industries, Parks, Water and Environment Wes Ford assured that the closures are necessary to protect public health, Tasmania Examiner reports.
"Laboratory analysis from the affected area on the east coast showed that seven out of 10 rock lobster gut samples returned results above the health limits," Ford said. "Similarly, a number of the abalone samples returned readings of paralytic shellfish toxin above the health limits."
The government remains at a loss insofar as how the toxic algae species of dinoflagellate arrived at Tasmania and why it is thriving, stated Ford.
"Certainly, it's the first time that this species of algae has produced a toxic bloom in Tasmania," he said, ABC reports.
It first showed up earlier in November in a mussel farm on the east coast and has since spread. Shellfish farmers were the first to be affected, and the paralytic shellfish toxin outbreak is hitting them right as the spawning period approaches – and right before the period of peak demand at Christmas, oyster growers say.
Meanwhile, customers worry that their seafood may not be safe to eat, according to rock lobster processors. But they assure that there are no rock lobsters from that area on sale, as the season did not open there.
But there is still recreational fishing to worry about. Director of Public Health Roscoe Taylor warned consumers to stay away from the gut of rock lobster or the gut of abalone harvested from the east coast between Marion Bay and Eddystone Point, plus oysters, clams or mussels taken from the area recreationally. Periwinkles, sea urchins or crabs from this area should also be avoided.
For now, rock lobster from the south, west and north-west coasts is filling the gap and might be enough to satisfy demand come Christmas.
John Sansom from the Rock Lobster Fishermen's Association and the rest of the industry worry the toxin could keep spreading and affecting more fisheries.
"The worst case scenario at the moment is if rock lobsters test positive to PST outside the boundaries we have at the moment, that we'll have to extend the closures," he said.
On the other hand, University of Tasmania biologist Chris Bolch thinks the toxin is on its way out.
"All the data suggests we saw a peak probably about four weeks ago and that it's dissipating," he said.
Still, the fishing grounds in question may not be open for harvesting again for weeks.
- Mussels contaminated with shellfish toxin
By Natalia Real